| PDF Pages<\/th>\n | PDF Title<\/th>\n<\/tr>\n | ||||||
|---|---|---|---|---|---|---|---|
| 2<\/td>\n | undefined <\/td>\n<\/tr>\n | ||||||
| 4<\/td>\n | CONTENTS <\/td>\n<\/tr>\n | ||||||
| 8<\/td>\n | FOREWORD <\/td>\n<\/tr>\n | ||||||
| 10<\/td>\n | 1 Scope 2 Normative references 3 Terms and definitions, symbols and indices, and formulae <\/td>\n<\/tr>\n | ||||||
| 11<\/td>\n | 4 Positive-sequence, negative-sequence and zero-sequence impedances ofelectrical equipment 4.1 General 4.2 Overhead lines, cables and short-circuit current-limiting reactors Figures Figure 1 \u2013 Positive-sequence and zero-sequence impedances of an overhead line (one circuit) and cable (cross-bonded) <\/td>\n<\/tr>\n | ||||||
| 12<\/td>\n | 4.3 Transformers 4.3.1 General Figure 2 \u2013 Positive-sequence and zero-sequence impedance of a short-circuit current-limiting reactor <\/td>\n<\/tr>\n | ||||||
| 13<\/td>\n | Figure 3 \u2013 Positive-sequence and zero-sequence system impedances of a two-winding transformer YNd5 <\/td>\n<\/tr>\n | ||||||
| 14<\/td>\n | Tables Table 1 \u2013 Examples for equivalent circuit-diagrams of transformers in the positive-sequence and the zero-sequence system <\/td>\n<\/tr>\n | ||||||
| 17<\/td>\n | 4.3.2 Example Figure 4 \u2013 Equivalent circuits of a three-winding network transformer Table 2 \u2013 Approximations for the ratios X(0)T\/XT of two- and three-winding transformers <\/td>\n<\/tr>\n | ||||||
| 19<\/td>\n | 4.4 Generators and power station units 4.4.1 General <\/td>\n<\/tr>\n | ||||||
| 21<\/td>\n | Figure 5 \u2013 Short circuit at the high-voltage side of a power station unit with on-load tap changer <\/td>\n<\/tr>\n | ||||||
| 22<\/td>\n | 4.4.2 Example <\/td>\n<\/tr>\n | ||||||
| 24<\/td>\n | 5 Calculation of short-circuit currents in a low-voltage system Un = 400 V 5.1 Problem 5.2 Determination of the positive-sequence impedances 5.2.1 Network feeder Figure 6 \u2013 Low-voltage system Un = 400 V with short-circuit locations F1, F2, F3 <\/td>\n<\/tr>\n | ||||||
| 25<\/td>\n | 5.2.2 Transformers Table 3 \u2013 Data of electrical equipment for the example in Figure 6 \u2013 Positive-sequence and zero-sequence impedances (Z(2) = Z(1)) <\/td>\n<\/tr>\n | ||||||
| 26<\/td>\n | 5.2.3 Lines (cables and overhead lines) 5.3 Determination of the zero-sequence impedances 5.3.1 Transformers <\/td>\n<\/tr>\n | ||||||
| 27<\/td>\n | 5.3.2 Lines (cables and overhead lines) 5.4 Calculation of I”k and ip for three-phase short circuits 5.4.1 Short-circuit location F1 <\/td>\n<\/tr>\n | ||||||
| 28<\/td>\n | Figure 7 \u2013 Positive-sequence system (according to Figure 6) for the calculation of I”k at the short-circuit location F1 <\/td>\n<\/tr>\n | ||||||
| 29<\/td>\n | 5.4.2 Short-circuit location F2 <\/td>\n<\/tr>\n | ||||||
| 30<\/td>\n | 5.4.3 Short-circuit location F3 5.5 Calculation of I”k1 and ip1 for line-to-earth short circuits 5.5.1 Short-circuit location F1 <\/td>\n<\/tr>\n | ||||||
| 31<\/td>\n | 5.5.2 Short-circuit location F2 5.5.3 Short-circuit location F3 Figure 8 \u2013 Positive-sequence, negative-sequence and zero-sequence system with connections at the short-circuit location F1 for the calculation of I”k1 <\/td>\n<\/tr>\n | ||||||
| 32<\/td>\n | 5.6 Collection of results Table 4 \u2013 Short-circuit impedances and short-circuit currents Table 5 \u2013 Joule integral depending on Tk at the short-circuit location F2 and F3 <\/td>\n<\/tr>\n | ||||||
| 33<\/td>\n | 6 Calculation of three-phase short-circuit currents in a medium-voltage system \u2013 Influence of asynchronous motors 6.1 Problem 6.2 Complex calculation with absolute quantities <\/td>\n<\/tr>\n | ||||||
| 34<\/td>\n | Figure 9 \u2013 Medium-voltage network 33 kV\/6 kV: data <\/td>\n<\/tr>\n | ||||||
| 35<\/td>\n | Table 6 \u2013 Calculation of the short-circuit impedances of electrical equipment and Zk(T1,T2) at the short-circuit location F, without motors (circuit-breakers CB1 and CB2 are open) <\/td>\n<\/tr>\n | ||||||
| 37<\/td>\n | 6.3 Calculation with per-unit quantities <\/td>\n<\/tr>\n | ||||||
| 38<\/td>\n | Table 7 \u2013 Calculation of the per-unit short-circuit reactances of electrical equipment and *Xk(T1,T2) at the short-circuit location F <\/td>\n<\/tr>\n | ||||||
| 39<\/td>\n | 6.4 Calculation with the superposition method <\/td>\n<\/tr>\n | ||||||
| 41<\/td>\n | Figure 10 \u2013 Short-circuit current I”K(T1,T2)S calculated by the superposition method (S) compared with I”K(T1,T2)IEC calculated by the IEC method of equivalent voltage source at the short-circuit location, depending on the load Sb and the voltage Ub <\/td>\n<\/tr>\n | ||||||
| 42<\/td>\n | 7 Calculation of three-phase short-circuit currents for a power station unit and the auxiliary network 7.1 Problem Figure 11 \u2013 Short-circuit current I”KS calculated by the superposition method (S) compared with calculated by the I”kIEC method of equivalent voltage source at the short-circuit location, depending on the transformation ratio t before the short circuit <\/td>\n<\/tr>\n | ||||||
| 44<\/td>\n | Figure 12 \u2013 Power station unit (generator and unit transformer with on-load tap-changer) and auxiliary network with medium- and low-voltage asynchronous motors: data <\/td>\n<\/tr>\n | ||||||
| 45<\/td>\n | 7.2 Short-circuit impedances of electrical equipment 7.2.1 Network feeder 7.2.2 Power station unit <\/td>\n<\/tr>\n | ||||||
| 46<\/td>\n | 7.2.3 Auxiliary transformers <\/td>\n<\/tr>\n | ||||||
| 47<\/td>\n | 7.2.4 Low-voltage transformers 2,5 MVA and 1,6 MVA <\/td>\n<\/tr>\n | ||||||
| 49<\/td>\n | Table 8 \u2013 Data of transformers 10 kV\/0,73 kV and 10 kV\/0,42 kV, data of low-voltage motor groups and partial short-circuit currents of these motor groups on busbars B and C respectively <\/td>\n<\/tr>\n | ||||||
| 50<\/td>\n | Table 9 \u2013 Data of medium-voltage asynchronous motors and their partial short-circuit currents at short-circuit locations on busbars B and C respectively <\/td>\n<\/tr>\n | ||||||
| 51<\/td>\n | 7.2.5 Asynchronous motors 7.3 Calculation of short-circuit currents 7.3.1 Short-circuit location F1 <\/td>\n<\/tr>\n | ||||||
| 52<\/td>\n | 7.3.2 Short-circuit location F2 <\/td>\n<\/tr>\n | ||||||
| 53<\/td>\n | 7.3.3 Short-circuit location F3 <\/td>\n<\/tr>\n | ||||||
| 54<\/td>\n | Figure 13 \u2013 Positive-sequence system for the calculation of the short-circuit currents at the location F3 (see Figure 12) <\/td>\n<\/tr>\n | ||||||
| 57<\/td>\n | 7.3.4 Short-circuit location F4 Figure 14 \u2013 Positive-sequence system for the calculation of the short-circuit currents at the location F4 (see Figure 12) <\/td>\n<\/tr>\n | ||||||
| 59<\/td>\n | 7.3.5 Short-circuit location F5 Figure 15 \u2013 Positive-sequence system for the calculation of the short-circuit currents at the location F5 (see Figure 12) <\/td>\n<\/tr>\n | ||||||
| 61<\/td>\n | 8 Calculation of three-phase short-circuit currents in a wind power plant 8.1 General 8.2 Problem <\/td>\n<\/tr>\n | ||||||
| 62<\/td>\n | 8.3 Data and short-circuit impedances of electrical equipment Figure 16 \u2013 Windfarm with ten wind power station units <\/td>\n<\/tr>\n | ||||||
| 63<\/td>\n | Table 10 \u2013 Data and impedances of the electrical equipment (see Figure 16) referred to the 20 kV side <\/td>\n<\/tr>\n | ||||||
| 64<\/td>\n | 8.4 Nodal admittance and nodal impedance matrices Table 11 \u2013 The diagonal elements of the nodal admittance matrices for the three variants in 1\/\u03a9 <\/td>\n<\/tr>\n | ||||||
| 65<\/td>\n | 8.5 Short-circuit currents for the wind power plant with ten wind power station units WD Table 12 \u2013 Short-circuit impedances and short-circuit currents at F1 to F14 for wind power stations units with doubly fed asynchronous generators WD <\/td>\n<\/tr>\n | ||||||
| 66<\/td>\n | Figure 17 \u2013 Equivalent circuit diagram for the calculation of the short-circuit current at the location F1 without the consideration of the internal wind power plant cables (values are related to the 20 kV voltage level), variant 1 Table 13 \u2013 Short-circuit impedances and short-circuit currents at F1 to F3 for wind power stations units with doubly fed asynchronous generators WD neglecting the internal wind power plant cables <\/td>\n<\/tr>\n | ||||||
| 67<\/td>\n | 8.6 Short-circuit currents for the wind power plant with ten wind power station units WF <\/td>\n<\/tr>\n | ||||||
| 68<\/td>\n | Table 14 \u2013 Quotients Zij\/ZkFi for i = 1 to 14 and j = 3\u20266, 8\u202610, 12\u202614 and the sum of the columns Table 15 \u2013 Short-circuit impedances and short-circuit currents at F1 to F14 for wind power stations units with full size converters WF <\/td>\n<\/tr>\n | ||||||
| 69<\/td>\n | Figure 18 \u2013 Equivalent circuit diagram for the calculation of the short-circuit current at the location F1 without the consideration of the internal wind power plant cables (values are related to the 20 kV voltage level), variant 2 <\/td>\n<\/tr>\n | ||||||
| 70<\/td>\n | 8.7 Short-circuit currents for the wind power plant with five wind power station units WD and five wind power station units WF Table 16 \u2013 Short-circuit impedances and short-circuit currents at F1 to F3 for wind power stations units with full size converters WF neglecting the internal wind power plant cables <\/td>\n<\/tr>\n | ||||||
| 71<\/td>\n | Table 17 \u2013 Quotients Zij\/ZkFi for i = 1 to 14 and j = 3, 10, 12, 13, 14 and the sum of the columns Table 18 \u2013Short-circuit impedances and short-circuit currents at F1 to F14 for five wind power stations units with doubly fed asynchronous generators WD and five wind power station units with full size converters WF <\/td>\n<\/tr>\n | ||||||
| 72<\/td>\n | Figure 19 \u2013 Equivalent circuit diagram for the calculation of the short-circuit current at the location F1 without the consideration of the internal wind power plant cables (values are related to the 20 kV voltage level), variant 3 <\/td>\n<\/tr>\n | ||||||
| 73<\/td>\n | Table 19 \u2013 Short-circuit impedances and short-circuit currents at F1 to F3 for five wind power stations units with doubly fed asynchronous generators WD and five wind power station units with full size converters WF neglecting the internal wind power plant cables <\/td>\n<\/tr>\n | ||||||
| 74<\/td>\n | 9 Test network for the calculation of short-circuit currents with digital programs in accordance with IEC 60909-0 9.1 General <\/td>\n<\/tr>\n | ||||||
| 75<\/td>\n | 9.2 High-voltage test network 380 kV\/110 kV\/30 kV\/10 kV 9.2.1 Network topology and data <\/td>\n<\/tr>\n | ||||||
| 76<\/td>\n | Figure 20 \u2013 High-voltage AC test network 380 kV\/110 kV\/30 kV\/10 kV <\/td>\n<\/tr>\n | ||||||
| 78<\/td>\n | 9.2.2 Short-circuit impedances of electrical equipment Table 20 \u2013 Overhead lines and cables <\/td>\n<\/tr>\n | ||||||
| 79<\/td>\n | 9.3 Results 9.3.1 General Table 21 \u2013 Impedances (corrected if necessary) of the electrical equipment (see Figure 20) referred to the 110 kV side with Z(2) = Z(1) <\/td>\n<\/tr>\n | ||||||
| 80<\/td>\n | 9.3.2 Three-phase short-circuit currents 9.3.3 Line-to-earth short-circuit currents Table 22 \u2013 Results I”k, ip, Ib and Ik <\/td>\n<\/tr>\n | ||||||
| 81<\/td>\n | Table 23 \u2013 Results I”k and ip1 <\/td>\n<\/tr>\n | ||||||
| 82<\/td>\n | Bibliography <\/td>\n<\/tr>\n<\/table>\n","protected":false},"excerpt":{"rendered":" Short-circuit currents in three-phase AC systems – Examples for the calculation of short-circuit currents<\/b><\/p>\n |